Air cleaner



March 23, 1943.

G. N. CLARK ETAL AIR CLEANER Filed Aug. 2, 1940 2 Sheets-Sheet 1 3 y 2 7 E ,0 3 4 w "I, 7 4 7 6 K 9 W% 6 I .Q w Z WI y 4 g x rlv i1 fi w d P W 1 BY Era/(2 Pgzsgica March'23, 1943. s. N. CL-ARK ET Al- AIR CLEANER Filed Aug. 2, 1940 2 Sheets-Sheet 2 INVENTORS Q, I (Zia/b 6072:? BY [/7285 files UNITED AIR CLEANER Denver,

Application August 2, 1

12 Claims.

The principal object of this invention is to provide a self-wetting air filter, having numerous pile fibers for contact with the air stream. Generally speaking, this is accomplished by stretching yarn free between spaced upper and lower supports with adjacent strands in substantial contact to form a highly pervious wall that will pass air freely, will catch entrained solids from the air, and will transmit liquid rapidly along the several strands to keep them properly moistened or oiled, as the case may be. Preferably, the yarn is wound up and down about the supports to form a helix or helices, stretched fiat and free between the supports to form twowalls or a hollow wall, in which the up anddown strands are in substantial contact and form a barrier to the passage of any solid matter in the air stream. drical form will be preferred with the supports forming the end portions and held apart by some suitable spacer of open work construction. In others, a fiat form will be preferred, but these things lie entirely within the. choice of the designer or the customer.

In the drawings, Fig. l is a vertical section through one form of the filter diagrammatically connected with an internal combustion engine;

Fig. 2 is a horizontal section on the line 2-2 of Fig. l;

Fig. 3 is an enlarged fragment of the filter element showing the supports and spacers in section and the yarn in process of being wound about the supports; and

Fig. 4 is a vertical section through an alternative arrangement of filter and easing.

These specific illustrations and the corresponding description are intended for the purpose of disclosure only, and should not be used to impose unnecessary limitations on the claims.

In Fig. 1, there is a base castin Ill, having an inlet for air H and an outlet l2. In order to interpose the filter proper between the inlet and the outlet, the latter is turned down at l3, and

a filter seat It is machined to surround the lower end of the outlet. Surrounding this seat and spaced at a considerable distance from it is a casing seat l5 also of circular form, machined on the lower side of the base, and it receives a casing comprising a cylindrical wall l6 and a dished bottom ll welded to the wall at Hi. The casing is held in place by a bolt l3 having its upper end screwed into a socket 7.0 in the base and its lower end equipped with a wing nut 2| bearing against the outsideof the dishedbottom ll.

George N. Clark and] Ernest It. Lesagc,

Colo.

940, Serial No. 349,559

In many applications, a cylinfilter element proper, generally indicated by F, and a cylindrical fire screen, generally indicated by S, are assembled between similar sheet metal rings 22 and 23 of channel crosssection, the flanges 24 and 25 thereof cooperating with the respective end portions of the filter and screen, as will appear clearly in Fig. 1..

This sub-assembly is supported by a follower 26 of sheet metal, dished at the middle and provided with a fiat flange 2'! bearing against the ring 23. A coil spring 28 between the bottom I! and the follower 26 serves to press the subassembly against the filter seat l4 and maintain it in proper-position.

The upper side of the follower 26 is provided with a funnel-shaped sheet metal guide 29, welded to it to serve as a guide for the lower end of the bolt H! as the casing with the subassembly is being brought into place with respect to the base ill.

This arrangement is especially suited for internal combustion engines, and, when applied, the outlet i2 will be connected with a carbureter 3| on the engine 32, as indicated diagrammatically at the right of Fig. 1.

The preferred construction of the filter element is shown in Fig. 3, and includes upper and lower supports 33 and 34 in the form of rings of sheet metal, channel-shaped in cross section and having their flanged portions 35 crimped about the respective ends of a cylinder 36 of expanded metal having a thickness much less than the cross section of the supports 33 and 3d. This cylinder merely forms a spacer for the supports and is made as open as possible to obstruct the fiow of air a minimum.

The actual filtering material 'is yarn 31 wound lengthwise to the cylinder about the supports 33 and 34 in a sort of helix stretched fiat at the inside and the outside to bring adjacent strands substantially parallel and in substantial contact throughout their length as they stretch freely from one support to another. In actual manufacture, it has been found most feasible to wind the yarn in four strands, thus laying up four spirals side by side, or interlaced, but that is purely amatter of choice in,manufacturing and does not materially affect the operation of the t to suit individual able not to have any transverse yarn for the same reason.

In practice, it has been found that fourstranded Wool yarn, having 74 yards per ounce, is very satisfactory for filters to be used with internal combustion engines either at the intake or at the breather. This yarn has very extensive pile fibers and when laid up as described presents a pile surface that bars all solid matter from passage with the air while being itself extremely pervious to the mum of resistance to the flow.

The fire screen is a fine wire netting to prevent a back-fire from the carburetor setting fire to the oiled yarn.

It has been found good practice to solder the ends of the fire screen to the-flange 25 of each of the rings 22 and 23, making the sub-assembly stay intact, whereby, when the unit is being handled, the yarn is not damaged by being cut or bruised when the support is brought into con tact with metal objects or cement floors as are commonly used in garages.

In the assembly shown in Fig. 1, a small amount of oil is put in the bottom of the casing to wet the lower ends of the yarn strands, which by capillary attraction quickly feed the oil upwardly and maintain the whole in uniformly wetted condition. Within the casing and welded to the bottom I1 is an overflow pipe 38, which limits the upper level of the oil in the casing.

' When the filter is used to introduce a liquid into a gas stream, the liquid will be supplied either from the bottom or from the top and will be quickly fed along the parallel strands, and the filter will be kept uniformly wetted from top to bottom.

In Fig. 4 is an alternative arrangement for internal combustion engines including an inlet casing 39 and an outlet casing 40 spaced apart with the filter element 4| and the screen cylinder 42 arranged between them substantially as shown. The inlet casing has a liquid chamber 43 closed at the top by a filling plug 44 and having feed openings 45 in the bottom to feed the liquid to the yarn in the filter element 4|.

The outlet casing has a liquid receptacle 45, the bottom of which is in contact with the closure element and the screen 42. Within the screen, the outlet casing includes a tube or pipe 46 to be connected with the carbureter of the internal combustion engine. The inlet casing includes a flange 41, slightly larger than the receptacle 45 of the outlet casing, and serves to form with that casing aninlet for the air to the outside of the filter element. The length of the flange 41 will be varied by designs, and the choice is indicated by the dotted lines in Fig. 4.

The connection between the inlet and outlet casings and the spacing for the supports of the filter element have been omitted in the interest of clearness.

Various other forms could be readily designed preferences and particular conditions.

After a suitable period of operation, the filter yarn will become more or less clogged with solid matter, but can be readily cleaned by washing in any suitable solvent, such as gasoline or other higher volatile for filters used in gasoline engines, and kerosene or 300 degree oil for filters used in Diesel engines.

The operation is simple. The wing nut 2| is taken off in the form shown in Figs. 1 and 2, and the casing with the filter unit removed by air and offering a miniassembled as shown.

We claim: 1. In a device circu cylinder, and yarn wound about the supports to outer wallof the inner yarn cylinder being spaced from said spacing means.

3. In a device of the class described, spaced circular ring supports, one above the other, spacing means between said supports and forming therewith a skeleton cylinder, and yarn supports and forming two concentric yarn cylinders having the same numyarn being of the same cross-sectional area, and

cent strands of the more open section.

5. In a device of the class described, a casing having an inlet and an outlet for air, a filter composed of unwoven strands of yarn material;

between the inlet and the outlet, and

passage of broken pieces of said yarn material and to prevent burning of said combustible filter through backfires.

6. In a device of the class described, spaced circular ring supports, one above the other, spacing means between said supports and forming therewith a skeleton cylinder, and yarn wrapped are substantially parallel and with adjacent strands in substantial contact for their entire lengths.

7. In a device of the class described, spaced circular ring supports, one above the other, spacing means between said supports and forming therewith a skeleton cylinder, and strands of yarn of substantially parallel contacting strands side by side spaced inwardly from said skeleton cylinder and spaced from said first-named strands. 8. In a device of the class described, a casing having an inlet and an outlet for air, a filter between the inlet and the outlet including upper and lower circular ring supports with spacing means therebetween, and-yarn stretched between the supports to form two concentric circular walls of strands side by side in substa tial contact, and means including a reservoir for containing a liquid into which the lower portions of said strands extend for supplying a liquid to the yarn. 9. In 'a device of the class described, acasing having an inlet and an outlet for air, a filter between the inlet and outlet including upper and lower circular ring supports and spacing means overhung both inside and outside by said ring supports and forming therewith a skeleton cylin- I der, and yarn wound about the supports to form inner and outer yarn cylinders with adjacent strands extending vertically in contact for substantially their entire length, said cylinder walls being spaced apart by the thickness of said ring supports whereby each yarn cylinder clears said spacing means, and means to supply a liquid to said yarn by capillary attraction only.

10. In a device of the class described, a casing having an inlet and an outlet for air adjacent its upper end, a filter between the inlet and the outlet including upper and lower circular ring supports with spacing means therebetween and yarn stretched between the supports to form two concentric circular walls of strands spaced apart, the strands of each wall being side by side in substantial contact for their entire lengths, the outer wall having its upper end inwardly of and adjacent the outlet, whereby the more closely spaced strands of the inner wall .will filter out any material that may pass through the more loosely spaced strands of the outer wall.

.11. In a device of the class described, spaced circular supports one above the other, spacing means between said supports and forming therewith a skeleton cylinder, and strands of combustible yam stretched between the supports to form a circular wall of substantially parallel strands side by side outside the said circular supports and another circular wall of substantially paral lel strands side by side inside of said circular supports, whereby said inner yarn wall will be closer built and will filter out any material that may have passed through the outer yarn cylinder wall, and a metallic screen adjacent the inner yarn cylinder wall to prevent the inward passage of broken pieces of said yarn and to prevent the burning of saidyarn walls through backfires. 12. 'In an air cleaner for internal combustion engines, the combination of a casing having an inlet and an outlet for air, a filter between the inlet and the outlet, said filter comprisingmore openv and less open sections in series, both. of said sections being composed of substantially parallel stretched strands of yarn, the less open section having adjacent yarn strands in closer contact than theadjacent strands of the more open secandmetallic screen means in series with said two sections of said filter to prevent the passage of foreign matter from said filter to said engine and to prevent combustion of said filter through backfires, said less open section being between the screen and the more open section and said screen being arranged inwardly of said sections a GEORGE N. CLARK.

ERNEST R. LESAGE. 

